1. Field of the Invention
The present invention relates to an electronic cotrolled heat cooking apparatus and a method of controlling the same. More specifically, the present invention relates to an improvement of a heat cooking apparatus employing a microprocessor for the purpose of controlling a heating condition and a method of controlling the same.
2. Description of the Prior Art
A microwave oven is well-known as an example of a heat cooking apparatus. Of late, a microprocessor implemented by a large scale integration has been employed in such microwave oven for the purpose of performing various cooking functions with a simple circuit configuration and through simple manipulation.
In general, if it is possible to control a heat cooking operation responsive to the temperature of a material being cooked in a heat cooking apparatus, then such a cooking apparatus would be of extreme use.
Conventionally, as such a kind of cooking apparatus, such a cooking apparatus as employing a temperature probe as a temperature measuring means has been proposed and put into practical use. With such a type of cooking apparatus, a temperature probe including a thermistor is inserted into a material being cooked and then the material being cooked in such a state is subjected to heat energy, whereupon control is made of radiation of heat energy responsive to the temperature measured by means of the temperature probe.
Nevertheless, a disadvantage is encountered in such a type of cooking apparatus that since a temperature probe is penetrated into a material being cooked an appearance of the material being cooked is undesirably degraded while the temperature probe need be made clean in using the same. Fatally, a further disadvantage is encountered that a temperature control cannot be made to such a material being cooked as a frozen food material in which a temperature probe can not be inserted.
On the other hand, utilization of an infrared detecting device had been proposed as a temperature measuring means in place of utilizing a temperature probe. Utilization of an infrared detecting device is disclosed in, for example, Japanese Patent Publication No. 24447/1973, published for opposition July 21, 1973, which is of a Japanese patent application filed Jan. 28, 1970 by Hitachi Ltd.. The above referenced Japanese Patent Publication No. 24447/1973 discloses that an infrared radiation emitted from a material being cooked is detected by an infrared detecting device and energization of a magnetron is interrupted upon detection of saturation of the infrared radiation intensity. Thus, the above referenced Japanese patent publication is merely aimed to stop heat cooking only upon detection of saturation of the infrared radiation intensity and can not control a heat cooking operation accurately responsive to the temperature of the material being cooked. Conversely described, even if it is desired to stop heating a material being cooked at a given temperature lower than that corresponding to saturation of the infrared radiation intensity, such as typically in case of defrosting a frozen material, the above referenced Japanese patent publication can not be employed.
Thus, a conventional approach employing an infrared detecting device can not make an accurate temperature control, mainly because a control scheme becomes complicated, which makes it difficult to put the apparatus into practical use.